Refactor: NoActor to SimpleCheck with compile-time environment check

This prevents security issues where :create/:read without actor would
be allowed in production. Now all operations require an actor in production.
This commit is contained in:
Moritz 2026-01-08 22:54:49 +01:00
parent 70729bdd73
commit 6846363132
Signed by: moritz
GPG key ID: 1020A035E5DD0824
2 changed files with 45 additions and 30 deletions

View file

@ -300,11 +300,12 @@ defmodule Mv.Membership.Member do
# Authorization Policies
# Order matters: Most specific policies first, then general permission check
policies do
# SYSTEM OPERATIONS: Allow operations without actor (seeds, tests, system jobs)
# This must come first to allow database seeding and test fixtures
# IMPORTANT: Use bypass so this short-circuits and doesn't require other policies
# SYSTEM OPERATIONS: Allow CRUD operations without actor
# In test: All operations allowed (for test fixtures)
# In production: Only :create and :read allowed (enforced by NoActor.check)
# :read is needed for internal Ash lookups (e.g., relationship validation during user creation).
bypass action_type([:create, :read, :update, :destroy]) do
description "Allow system operations without actor (seeds, tests)"
description "Allow system operations without actor (seeds, tests, internal lookups)"
authorize_if Mv.Authorization.Checks.NoActor
end

View file

@ -2,22 +2,27 @@ defmodule Mv.Authorization.Checks.NoActor do
@moduledoc """
Custom Ash Policy Check that allows actions when no actor is present.
This is primarily used for:
- Database seeding (priv/repo/seeds.exs)
- Test fixtures that create data without authentication
- Background jobs that operate on behalf of the system
**IMPORTANT:** This check ONLY works in test environment for security reasons.
In production/dev, ALL operations without an actor are denied.
## Security Note
This check should only be used for specific actions where system-level
access is appropriate. It should always be combined with other policy
checks that validate actor-based permissions when an actor IS present.
This check uses compile-time environment detection to prevent accidental
security issues in production. In production, ALL operations (including :create
and :read) will be denied if no actor is present.
For seeds and system operations in production, use an admin actor instead:
admin_user = get_admin_user()
Ash.create!(resource, attrs, actor: admin_user)
## Usage in Policies
policies do
# Allow seeding and system operations
policy action_type(:create) do
# Allow system operations without actor (TEST ENVIRONMENT ONLY)
# In test: All operations allowed
# In production: ALL operations denied (fail-closed)
bypass action_type([:create, :read, :update, :destroy]) do
authorize_if NoActor
end
@ -29,32 +34,41 @@ defmodule Mv.Authorization.Checks.NoActor do
## Behavior
- Returns `{:ok, true}` when actor is nil (allows action)
- Returns `{:ok, :unknown}` when actor is present (delegates to other policies)
- `auto_filter` returns nil (no filtering needed)
- In test environment: Returns `true` when actor is nil (allows all operations)
- In production/dev: Returns `false` when actor is nil (denies all operations - fail-closed)
- Returns `false` when actor is present (delegates to other policies)
"""
use Ash.Policy.Check
use Ash.Policy.SimpleCheck
# Compile-time check: Only allow no-actor bypass in test environment
@allow_no_actor_bypass Mix.env() == :test
# Alternative (if you want to control via config):
# @allow_no_actor_bypass Application.compile_env(:mv, :allow_no_actor_bypass, false)
@impl true
def describe(_opts) do
"allows actions when no actor is present (for seeds and system operations)"
end
@impl true
def strict_check(actor, _authorizer, _opts) do
if is_nil(actor) do
# No actor present - allow (for seeds, tests, system operations)
{:ok, true}
if @allow_no_actor_bypass do
"allows actions when no actor is present (test environment only)"
else
# Actor present - let other policies decide
{:ok, :unknown}
"denies all actions when no actor is present (production/dev - fail-closed)"
end
end
@impl true
def auto_filter(_actor, _authorizer, _opts) do
# No filtering needed - this check only validates presence/absence of actor
nil
def match?(nil, _context, _opts) do
# Actor is nil
if @allow_no_actor_bypass do
# Test environment: Allow all operations
true
else
# Production/dev: Deny all operations (fail-closed for security)
false
end
end
def match?(_actor, _context, _opts) do
# Actor is present - don't match (let other policies decide)
false
end
end